The Agusta AW 109 is a lightweight, twin-engine, eight-seat multi-purpose helicopter built by Anglo-Italian manufacturer AgustaWestland.
Developed as the A109 Agusta, it has been in continuous production for 40 years. The AgustaWestland AW119 is a derivative of the AW109, the main difference being that it is powered only by a single engine instead.
AW 109 . Helicopter Design and Development
In the late 1960s, Agusta designed the A109 as a single-engine commercial helicopter. It was soon realized that a twin-engine design was needed and it was redesigned in 1969 with two turboshaft Allison 250-C14 engines.
A projected military version (the A109B) was considered early but Agusta initially chose not to pursue development, concentrating instead on the eight-seat A109C version. The first of three prototypes made their maiden flight on August 4, 1971. The test phase of development flights was protracted, leading to the first production aircraft being completed nearly four years later in April 1975. Production deliveries of the A109s began in early 1976.
After its release, the aircraft soon became a commercial success, often being used for roles other than light transport; this includes air ambulance and search and rescue roles. In 1975, Agusta returned to a possible military version, so trials were carried out between 1976 and 1977 using a total of five A109As equipped with Hughes Aircraft TOW missiles. Two military versions emerged of the program, one intended for light attack/close support missions and the other for ship operations.